Two defeats, a draw, two goals scored and seven conceded: three matches into Louis van Gaal’s Manchester United tenure and he has serious problems. Four of those seven goals were claimed by MK Dons on an abysmal night for the manager, his United “project” and the club, as his toothless team were dumped out of the Capital One Cup at the first possible stage.

Quite how the 20-times champions could be humiliated 4–0 by a League One side requires an inquest to answer. These were opponents who last season suffered more defeats in the league at Stadium MK – 10 – than the eight occasions they won.

Yet against United Karl Robinson’s men were quicker, hungrier and simply far better than their gilded opponents. How far United may continue to fall after this confidence-destroying result remains to be seen.

In the 2012-13 season, United won the title at a canter by 11 points. Less than 18 months later, on a wet Tuesday in Milton Keynes, they were dumped out of the third-tier competition in the second round for the first time since 1995. The focus may be on trying to regain a Champions League place but how remote that seems, with Van Gaal having overseen similarly dispiriting fare in the opening two Premier League matches.

In the first game Swansea City came to Old Trafford and won 2-1 to hand them their inaugural home defeat of the Premier League era. At Sunderland on Sunday the 3-5-2 Van Gaal switched United to during the summer again appeared ill-suited to the players he has to choose from as an unconvincing 1-1 draw was scraped.

Then came this result, which rival supporters will hardly allow United fans to forget. While a view may be held this was only the League Cup and that Van Gaal was without a clutch of injured players, there are serious arguments countering this. The XI he fielded were hardly a second string. It was a blend of young hopefuls and the senior players: David de Gea, Anderson, Danny Welbeck, Javier Hernández, Adnan Januzaj, who was an 18th-minute substitute, and Jonny Evans, the captain who had a particularly bad evening.

The Northern Irishman was at fault for two of the goals but Van Gaal may also want to look in the mirror. With no European football to nurse players through, why rest the A-listers – Robin van Persie, Wayne Rooney and Juan Mata? Or any of his squad’s other hardened operators, who would surely have avoided this calamity?

What was perhaps Van Gaal’s best hope of winning a trophy in his first campaign was thrown away. “It cost also [an opportunity of a] title,” he said afterwards, too late.

Will he tear up the 3-5-2 after his side’s dire displays performing it and to also accommodate Angel di María, the record £59.7m signing? And what must the Argentinian think of the MK Dons farrago?

As David May, the former United defender, said: “Its not often Man United go to a League One side and get beat 4-0. And, convincingly too.”

Di María is expected to make his debut at Burnley on Saturday. Turf Moor will be rocking as Van Gaal searches for a first win in four attempts. He – and United – dare not lose again.